This invention relates to a healing collar for use with endosseous dental implants. This healing collar can also serve as an insertion tool, and, in some embodiments, as part of an abutment. In the preferred embodiments, this healing collar includes two parts, a hollow collar member and a fixation screw member. The fixation screw member has a size and shape that allows the screw to pass into one end of the collar member, through the collar member, and into an internal, threaded passage inside the body of an endosseous dental implant upon which the healing collar placed. Inside the healing collar is an inwardly-projecting, annular flange or shelf to engage the bottom surface of the head on the screw member. In some embodiments, this flange or shelf is part of an annular projection that is threaded on its inner edge. These threads cooperate with a threaded tool to disengage the collar from the top of an implant, and is especially useful where the collar/implant interface is a snug, frictional connection.
This invention also relates to an implant package that includes a frictionally-fitting stopper for an endosseous implant container. At one end of the stopper is a first internal cavity for receiving and engaging frictionally the outer surface of the healing collar, and/or for engaging the internal, multi-sided internal cavity in the healing collar. In the package, the healing collar is connected to an endosseous dental implant by the fixation screw member, but can also be connected to the implant, alternatively, by frictional fit. In preferred embodiments, the other end of this stopper comprises a second internal cavity having a size and shape appropriate to receive a healing screw that frictionally engages the walls of the internal passage. This stopper allows an endosseous dental implant to be carried to a surgical site and to be initially inserted into the site without touching the surface of the implant. Following full seating of the implant into the site, by threading if a screw implant, or by tapping if a cylindrical implant, the stopper then serves as an insertion tool for the healing screw.
Alternative embodiments of this stopper receive and engage frictionally the outer surface or inner surface of a dental implant in the first internal cavity and the head of a fixation screw in the second internal cavity at the other end of the stopper.
The healing collar, in preferred embodiments, has a generally cylindrical exterior shape and is open at both ends. At a first end, the healing collar has a multi-sided internal cavity that is configured to fit over the top of an endosseous dental implant having at the top a multi-sided projection of complementary size and shape as in Core-Vent Corporation's SWEDE-VENT implant. Alternatively, the collar has a multi-sided projection at the first end that fits into an internal, multi-sided passage at the top of the implant, as in Core-Vent Corporation's SCREW-VENT (externally-threaded) and BIO-VENT (externally-unthreaded cylinder) brand implants.
At the second end of the healing collar is an internal, multi-sided surface that may receive and engage a multi-sided tool of complementary size and shape. This multi-sided surface may, for example, form a six-sided figure. In preferred embodiments, an internal, beveled or tapered surface lies above the internal multi-sided surface. This beveled or tapered region preferably has a degree of taper, with respect to the longitudinal axis of the sidewall of the implant, of about 12 degrees to about 18 degrees, but preferably about 15 degrees. This beveled or tapered region has a length sufficient to receive and engage a complementary, tapered portion of an abutment screw that has a tapered head portion that seats in the tapered, internal portion of the cavity at the second and of the healing collar.
The inwardly-projecting flange or shelf internal to, and between the first and second ends of the healing collar is of a size and shape to engage the head of a fixation screw member on one surface and, on the other surface, is of a size and shape appropriate for seating upon the top of an endosseous dental implant. Between these two surfaces, the flange preferably includes a threaded region for engaging a threaded shank on a screw or a tool designed to disengage the healing collar from the top of the implant if they frictionally fit together. The head of the fixation screw is preferably multi-sided. The space between this head and the internal multi-sided wall of the healing collar is sufficiently large to permit insertion of a multi-sided tool of complementary size and shape into the space to turn an implant connected to the healing collar into a passage in the jawbone of a patient. The outer wall of the healing collar is preferably cylindrical.
The fixation screw member, in preferred embodiments, has a head member that is multi-sided and of sufficiently small cross-sectional dimensions that a tool can fit over the head of the screw member, and can engage the multi-sided, internal walls of the healing collar. The head of the fixation screw may also have a slotted top or external or internal wrench-engaging surfaces and, in a preferred embodiment, an internal thread for receiving the threaded shank of a cover screw.
In preferred embodiments, the shank of a cover screw passes through the internal passage of the healing collar and screws into an internal passage in the body of the implant, or screws into internal threads in the head of a fixation screw member.
Preferred embodiments of the healing collar also can receive, and interfit with, a wide variety of abutment screws. One embodiment of such an abutment screw engages internal threads in a fixation screw member. Another embodiment engages internal threads inside the body of an endosseous dental implant, thus affixing the healing collar to the top of the implant. With these embodiments, the healing collar becomes part of the abutment. The abutment screw may have a straight or tapered upper end to receive a dental prosthesis, and, in some cases, an internally-threaded passage near the top to accept another screw that retains a dental prosthesis. The outer surface of the upper end may be multi-sided to allow engagement of a wrench or other tool, or may include an internal, multi-sided surface formed above, below or in the internal threads to receive a fastener to retain a dental prosthesis. Alternatively, the abutment screw can include a ball member for connection to a snap retainer in a dental prosthesis or a tapered solid member for attachment, as by cementation, of a dental crown or bridge.
The healing collar of this invention, in cooperation with a fixation screw member, a cover screw and/or an abutment screw, can engage a dental implant frictionally or non-frictionally. Frictional engagement results where the implant has a multi-sided projection at the top with a plurality of tapered sides, as disclosed in U.S. patent application No. 08/099,070, filed in the U.S. Patent & Trademark Office on Jul. 28, 1993. Alternatively, the healing collar may have a multi-sided projection that fits into an internal, multi-sided passage inside a dental implant where a plurality of the sides of the projection are tapered. See, for example, the tapered projection on the abutments disclosed in U.S. patent application No. 07/909,119 filed Jul. 6, 1992. Upon attachment to the top of the implant, the healing collar can function as an implant insertion tool alone, or as an insertion tool and a healing collar, if the collar is left in a patient's mouth immediately after insertion of the implant. In the latter case, the healing collar atop the implant is transmucosal, holding open the mucosal tissue above the implant during the healing period. This surgical protocol is commonly called "non-submerged healing" or "one-stage surgery".
The healing collar, when left atop a dental implant, can also function as part of an abutment. An abutment screw that interfits with the healing collar completes such an abutment. The healing collar may also function as an abutment collar even if the healing collar is detached from an implant promptly after insertion of the implant into a patient's mouth to allow submerged healing with the tissue covering the implant. The healing collar can be re-attached after a 3-6 month healing period, and used both for keeping mucosal tissue open during healing after the second surgery and/or as the collar of a 2-piece abutment.
Thus, the new healing collar provides many different functions: an implant insertion tool alone, a healing collar alone, an abutment part alone, an insertion tool/healing collar, an insertion tool/healing collar/abutment part, an insertion tool/abutment part, and a healing collar/abutment part. This collar can be configured to fit over implants that have external, multi-sided projections, or implants that have internal, multi-sided passages, and can be retained by a fixation screw for non-friction fit healing collars. These collars can also be configured to fit frictionally over implants that have tapered, multi-sided projections, or to engage internal implant passages frictionally with tapered projections on the collar itself.